The 35-page report recommends centralizing oversight of the more than 300 state and local prisons and jails where U.S. Immigration and Customs Enforcement houses detainees, rather than leaving it to ICE field offices. It mandates better medical assessment and monitoring of detainees. And it suggests increasing the use of alternatives to detention, such as electronic ankle bracelets, a system which costs an estimated $14 per detainee per day, rather than $100.

The report pointedly emphasizes that the purpose of immigration detention is not to punish people — as in the criminal incarceration system — but simply to process them for deportation. But the jails and prisons ICE uses treat detainees as if they were criminals, even though just 11 percent were felons who had violent criminal records.

Napolitano said that ICE is exploring using converted hotels and nursing homes as less restrictive detention centers. The report also recommends giving detainees greater access to legal counsel, visitation and religious practice.

The report was written by Dora Schriro, who Napolitano had appointed to oversee ICE detention policy but who left the job after just a month, apparently to tend to a family member with a medical problem. Napolitano announced today that Phyllis Coven, a long-time immigration administrator, will fill the job while a nationwide search is underway.

In her review, Schriro toured 25 detention facilities, met with inmates and employees, sat down with 100 non-profit groups and government officials and reviewed both federal data and human rights reports, several of which have been damning. A September analysis by the Migration Policy Institute questioned whether ICE was up to the task of properly managing its detention operations.